The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL x kg(-1) x min(-1)) and oxygen pulse (mL x beat(-1))) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3-4) and 46 controls. ⋯ During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC < or = 25% than in those with IC/TLC > 25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.
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Exhaled breath condensate (EBC) is a noninvasive method for the study of airway lining fluid. Nuclear magnetic resonance (NMR) spectroscopy can provide biochemical profiles of metabolites in biological samples. The aim of the present study was to validate the NMR metabonomic analysis of EBC in adults, assessing the role of pre-analytical variables (saliva and disinfectant contamination) and the potential clinical feasibility. ⋯ Each EBC sample clustered with corresponding samples of the same group, while presenting intergroup qualitative and quantitative signal differences (94% of the total variance within the data). In conclusion, the nuclear magnetic resonance metabonomic approach could identify the metabolic fingerprint of exhaled breath condensate in different clinical sets of data. Moreover, metabonomics of exhaled breath condensate in adults can discriminate potential perturbations induced by pre-analytical variables.
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Reactive oxygen species play an important role in the pathogenesis of acute lung injury and pulmonary fibrosis. The present authors hypothesise that edaravone, a free-radical scavenger, is able to attenuate bleomycin (BLM)-induced lung injury in mice by decreasing oxidative stress. Lung injury was induced in female ICR mice by intratracheal instillation of 5 mg x kg(-1) of BLM. ⋯ The fibrotic change in the lung on day 28 was ameliorated by edaravone, as evaluated by histological examination and measurement of hydroxyproline contents. In addition, edaravone significantly increased the prostaglandin E(2) concentration in BALF on day 2. In summary, edaravone was shown to inhibit lung injury and fibrosis via the repression of lipid hydroperoxide production and the elevation of prostaglandin E(2) production in the present experimental murine system.
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Desmosine (DES) and isodesmosine (IDES) are two unusual, tetrafunctional, pyridinium ring-containing amino acids involved in elastin cross-linking. Being amino acids unique to mature, cross-linked elastin, they are useful for discriminating peptides derived from elastin breakdown from precursor elastin peptides. According to these features, DES and IDES have been extensively discussed as potentially attractive indicators of elevated lung elastic fibre turnover and markers of the effectiveness of agents with the potential to reduce elastin breakdown. ⋯ The results of the application of DES and IDES as surrogate end-points in early clinical trials in COPD are also reported. Finally, recent advances in detection techniques, including liquid chromatography tandem mass spectrometry and high-performance capillary electrophoresis with laser-induced fluorescence, are discussed. These techniques allow detection of DES and IDES at very low concentration in body fluids other than urine, such as plasma or sputum, and will help the understanding of whether DES and IDES are potentially useful in monitoring therapeutic intervention in COPD.
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Peak oxygen uptake (V'(O(2))) remains the gold standard measurement of exercise capacity and has been associated with survival. A modified BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) index replacing the 6-min walk distance (6MWD) with V'(O(2)) as % predicted (mBODE%) has been developed and found to have excellent correlation with the conventional BODE index. The objectives of the present study were to compare the ability of the conventional BODE and the mBODE% to predict mortality in 444 patients with chronic obstructive pulmonary disease (COPD) followed for a mean+/-SD period of 71+/-34 months. ⋯ Logistic regression analysis with COPD survival as the dependent variable identified the BODE index, Charlson's and exercise capacity (in W) as variables associated with this outcome. In conclusion, the conventional BODE index, which uses the 6-min walk distance, predicts mortality in chronic obstructive pulmonary disease as well as the modified index using peak oxygen uptake. The results support the use of the simpler index, which includes the 6-min walk distance in the comprehensive evaluation of patients with chronic obstructive pulmonary disease.